A spindle motor performs the function of rotating a disk to enable an optical pickup which linearly reciprocates in an optical disk drive (ODD) to read data recorded on the disk.
FIG. 1 is a cross-sectional view illustrating essential parts of the conventional spindle motor.
Referring to FIG. 1, a bearing 15 is fixed at an interior of a bearing housing 13 formed at a base 11, and the bearing 15 is rotatably supported by a rotation shaft 17. A rotor 21 having a rotor yoke 21a and a magnet 21b is coupled to a periphery of the rotation shaft 17 exposed toward an upper surface of the bearing housing 13. The rotor 21 cooperatively rotate with a stator (not shown) fixed at the periphery of the bearing housing 13.
An outwardly extended hitching edge 13a is formed at an upper periphery of the bearing housing 13, and the rotor yoke 21a is coupled with a stopper 25 that prevents the rotation shaft 17 and the rotor 21 from being disengaged by being hitched at the hitching edge 13a. 
The conventional spindle motor thus configured is coupled to the rotor yoke 21a by way of welding, such that foreign objects generated from the welding are sticked to and stiffened at the stopper 25 or the rotor yoke 21a. The conventional spindly motor suffers from a disadvantage in that the foreign objects contact other parts to cause defects such as noise generation and the like, thereby degrading the reliability of the product.
The conventional spindle motor suffers from another disadvantage in that workability is cumbersome and inconvenient due to use of a welding machine for coupling the stopper 25 to the rotor yoke 21a. Furthermore, the conventional spindle motor suffers from still another disadvantage in that the welded coupling between the stopper 25 and the rotor yoke 21a makes it difficult for the stopper 25 to be separated from the rotor yoke 21a without damages to the stopper and the rotor yoke, whereby it is difficult to repair and re-use the stopper and the rotor yoke, and it is also uneconomical to dispose of the stopper and the rotor yoke due to high disposal cost.